The N15 looks durable and is a good youth trainer, more forgiving than the higher powered F16's. My concern is its a 310 lb boat, which is a good bit heavier than the F16 (~275 lbs) and nearly twice the weight of an A-Cat (165lbs). Tough to move that around on the beach solo. Certainly in breeze-on conditions and with the option to go back to the C-boards for non-foiling conditions it offers a lot of flexibility which is a good thing, but thats not a light boat to haul up the ramp solo at the end of the day.
310 seems pretty light to me, considering that is much lighter than the Hobie 16, with good beach wheels I get my Hobie 18 on and off the beach solo as long as the slope isn't too bad. Around 300 pounds might be the sweet spot for handling and durability with today's layup techniques.